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authorIndrajith K L2022-02-27 01:15:31 +0530
committerIndrajith K L2022-02-27 01:15:31 +0530
commit62ff5245c26c305e35a2903cc64a60cb20718e96 (patch)
tree9042f9917e77b584b0ceb421166221ef7777a5d1 /libs/moonshine/godsray.lua
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Initial Commit
* ECS - In-Progress * GameStates - Skeleton Implemented * Library Integrations - Completed * Levels - In-Progress
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+--[[
+The MIT License (MIT)
+
+Original code: Copyright (c) 2015 Josef Patoprsty
+Port to moonshine: Copyright (c) 2017 Matthias Richter <vrld@vrld.org>
+
+Based on work by: ioxu
+
+https://www.love2d.org/forums/viewtopic.php?f=4&t=3733&start=120#p71099
+
+Based on work by: Fabien Sanglard
+
+http://fabiensanglard.net/lightScattering/index.php
+
+Based on work from:
+
+[Mitchell]: Kenny Mitchell "Volumetric Light Scattering as a Post-Process" GPU Gems 3 (2005).
+[Mitchell2]: Jason Mitchell "Light Shaft Rendering" ShadersX3 (2004).
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
+]]--
+
+return function(moonshine)
+ local shader = love.graphics.newShader[[
+ extern number exposure;
+ extern number decay;
+ extern number density;
+ extern number weight;
+ extern vec2 light_position;
+ extern number samples;
+
+ vec4 effect(vec4 color, Image tex, vec2 uv, vec2 px) {
+ color = Texel(tex, uv);
+
+ vec2 offset = (uv - light_position) * density / samples;
+ number illumination = decay;
+ vec4 c = vec4(.0, .0, .0, 1.0);
+
+ for (int i = 0; i < int(samples); ++i) {
+ uv -= offset;
+ c += Texel(tex, uv) * illumination * weight;
+ illumination *= decay;
+ }
+
+ return vec4(c.rgb * exposure + color.rgb, color.a);
+ }]]
+
+
+ local setters, light_position = {}
+
+ for _,k in ipairs{"exposure", "decay", "density", "weight"} do
+ setters[k] = function(v)
+ shader:send(k, math.min(1, math.max(0, tonumber(v) or 0)))
+ end
+ end
+
+ setters.light_position = function(v)
+ light_position = {unpack(v)}
+ shader:send("light_position", v)
+ end
+
+ setters.light_x = function(v)
+ assert(type(v) == "number", "Invalid value for `light_x'")
+ setters.light_position{v, light_position[2]}
+ end
+
+ setters.light_y = function(v)
+ assert(type(v) == "number", "Invalid value for `light_y'")
+ setters.light_position{light_position[1], v}
+ end
+
+ setters.samples = function(v)
+ shader:send("samples", math.max(1,tonumber(v) or 1))
+ end
+
+ local defaults = {
+ exposure = 0.25,
+ decay = 0.95,
+ density = 0.15,
+ weight = 0.5,
+ light_position = {0.5,0.5},
+ samples = 70
+ }
+
+ return moonshine.Effect{
+ name = "godsray",
+ shader = shader,
+ setters = setters,
+ defaults = defaults
+ }
+end